According to OWASP, a man-in-the-middle (MITM) attack is when an attacker intercepts a communication between two systems and then splits the connection in two, injecting new data in between.

The 1,000 free apps were just a sample of the roughly 10,000 applications FireEye checked during the analysis. The results are just as unsettling on a larger scale as well:

“Roughly 4,000 (40%) [apps] use trust managers that do not check server certificates, exposing any data they exchange with their servers to potential theft,” writes the security team. “Furthermore, around 750 (7%) applications use hostname verifiers that do not check hostnames, implying that they are incapable of detecting redirection attacks where the attacker redirects the server request to a malicious webserver controlled by the attacker. Finally, 1,300 (13%) do not check SSL errors when they use Webkit.”

It’s up to developers to ensure their apps are protected from common vulnerabilities that could potentially lead to stolen data and information. Until then, think twice before downloading the latest free app.